🚀 go-pugleaf

93gke@williams.edu (oldwanda) writes:
: If this is true, then how can vendors push the 25Mhz chips to 33Mhz?
: Wouldn't they fail at the higher speeds since they were slow in
: testing?

Well, the vendor may have down-graded their chips (the chip may actually
work at 33MHz, but they labeled it at 25MHz because they needed more of
that bin).

More likely is that (as another poster mentioned) there is a guardband
built into the test.  Note that the IC must work at or above 25MHz, at
(possibly) 110C, 4.5V, etc.  If the board vendor knows that the case temp
won't go above a certain amount (good airflow, heatsink, etc.), and knows
that his supplies will be, say, 5.0V +/- 1% (not likely), then he could
push the chip higher in frequency with no ill effects.

Then again, the manufacturer probably put some 25MHz parts in his 33MHz board,
found that they worked, and shipped it.  :-)

Not good.

Scott Linn
scott@hpcvccl.cv.hp.com